Pure practical reason is the opposite to impure (or sensibly-determined) practical reason and appears in Immanuel Kant's Groundwork of the Metaphysics of Morals.
It is the reason that drives actions without any sensible incentives. Human reasoning chooses such actions simply because those actions are good in themselves; this is the nature of good will, which Kant argues is the only concept that is good without any justification, it is good in itself and is a derivative of a transcendental law which affects the way humans practically reason (see practical philosophy).
Famous quotes containing the words pure, practical and/or reason:
“There is no room for the impurities of literature in an essay.... the essay must be pure—pure like water or pure like wine, but pure from dullness, deadness, and deposits of extraneous matter.”
—Virginia Woolf (1882–1941)
“The ordinary literary man, even though he be an eminent historian, is ill-fitted to be a mentor in affairs of government. For ... things are for the most part very simple in books, and in practical life very complex.”
—Woodrow Wilson (1856–1924)
“Virtues are not emotions. Emotions are movements of appetite, virtues dispositions of appetite towards movement. Moreover emotions can be good or bad, reasonable or unreasonable; whereas virtues dispose us only to good. Emotions arise in the appetite and are brought into conformity with reason; virtues are effects of reason achieving themselves in reasonable movements of the appetites. Balanced emotions are virtue’s effect, not its substance.”
—Thomas Aquinas (c. 1225–1274)